The spelling and titles vary, e.g. "O My Hart And O My Hart", "O My Heart", etc.
This short song for the lute was composed by Henry VIII, who is known for marrying six wives and executing two of them. Henry was a fairly talented songwriter, but as his personal and political lives testify, his deeds seldom matched his fine words, as was undoubtedly the case here.
Suggestion credit: Alexander Baron - London, England